In many combines, the chaff is discharged through separate chaff distributors. The chaff distributors are relatively large blowers, which are usually driven hydraulically. Therefore, they are relatively costly and heavy. Thus, it can be advantageous to discharge the chaff through an existing straw chopper.
In DE 44 31 802 A it is proposed to feed the chaff through a back and forth moving inlet bottom of a horizontal conveyor screw, which feeds the chaff together with the straw to one or two straw choppers with vertical rotational axes.
In the publications DE 102 56 744 A and DE 103 03 503 A published later, it is proposed to convey the chaff by means of an oscillating base from the cleaning section to the inlet of the straw chopper, in DE 103 03 503 A with the simultaneous action of a rotating conveyor.
In U.S. Pat. No. 3,669,123 A, a combine is described, for which the chaff is fed by a slide connected to the cleaning shoe to the bottom of a straw chopper housing. The cleaning shoe shakes the slide. The straw chopper is located above the inlet for the chaff. The chaff is discharged by the air stream generated by the straw chopper.
According to U.S. Pat. No. 5,232,405 A, a conveyor belt is used for transporting the chaff from the cleaning section into a straw chopper.
In EP 0 958 727 A, it is proposed to transport the chaff released by the cleaning section through a cross auger initially outwards transverse to the direction of travel. Two partial streams are produced on both sides of the combine, which are transported backwards through additional augers and fed in the axial direction to a straw chopper with a horizontal rotational axis that is transverse to the direction of travel.
The above mentioned references disclose a mechanical feed of the chaff into the straw chopper. The chaff is introduced into the straw stream at the end of the conveyor by the force of gravity (DE 44 31 802 A, U.S. Pat. No. 5,232,405 A, DE 102 56 744 A), by a rotating conveyor (DE 103 03 503 A, EP 0 958 727 A), or by the suction effect of the straw chopper (U.S. Pat. No. 3,669,123 A). Here, transfer problems can occur.
In DE 36 20 747 A, a combine with a straw chopper is described. The straw released by the straw shakers slides along a straw guiding plate into the straw chopper. The straw guiding plate is set into a vibrating motion in order to improve conveyance. Here, likewise only one element is set in vibration, which transports the crop residue into the straw chopper, so that conveyance problems can occur with the transfer into the straw chopper.